The invention relates to a wind deflector for a vehicle.
Motor vehicles are known from series vehicle construction which have a fixed vehicle roof with at least one openable roof element. The openable roof element is usually referred to as a cover and is able to be shifted between a closed position which closes a roof opening and at least one open position which releases the roof opening at least partially. Here, the cover is allocated, for example, to a sliding and/or lifting roof, wherein the cover can be moved in the vehicle longitudinal direction and/or shifted in the vehicle vertical direction.
During vehicle operation, the released roof opening is flown over by air. It has thereby been shown that—if no corresponding counter measures are taken—a humming which is unpleasant for vehicle passengers can occur in the interior of the vehicle. The humming results due to periodic instabilities and pressure fluctuations in the shear layer flowing over the roof opening, which leads to a periodic pressure compensation in the interior. Such a humming can impair the driving comfort when the roof element is open.
DE 197 50 218 C2 discloses a method for suppressing periodic pressure changes in a cavity, for example an interior of a vehicle, which is flowed around by an external flow and is provided with an opening. It is thereby provided that a change of the flow direction of the external flow which is opposed to the current pressure change in the inside of the cavity is caused periodically and in phase. The change of the flow direction can thereby occur directly, for example using deflector wings, or indirectly, for example by transverse flow induced in proximity to the opening front edge.
A wind deflector for a vehicle is gleaned as known from DE 10 2008 036 887 A1. The wind deflector comprises at least one housing element and at least one deflector element, which is received at least partially in the housing element. Furthermore, the wind deflector comprises at least one actuator by means of which the deflector element is able to move in a linearly oscillating manner in at least one spatial direction relative to the housing element. Additionally, at least one sealing element is provided, by means of which the deflector element is sealed at least in a partial region against the housing element.
The object of the present invention is to create a wind deflector for a vehicle, by means of which humming noises in the interior of the vehicle can be kept particularly low when the roof opening is released.
In order to create a wind deflector for a vehicle, in particular a motor vehicle, by means of which humming noises in the interior of the vehicle can be kept particularly low, it is provided according to the invention that the sealing element is formed as a flexible membrane, which is arranged on the one hand on the housing element and on the other hand on the deflector element and is able to move with this. This means that the flexible membrane is moved during the oscillating movement of the deflector element. The deflector element can also be sealed particularly well against the housing element by means of the membrane such that unfavorable air flows can be prevented or at least kept low. It is thereby possible to influence the air flow in a targeted manner using the oscillating movement of the deflector element and to be able to induce disruptions in the air flow. Excessive, unpleasant humming which results from a periodic pressure compensation in the interior can hereby be prevented.
In particular, it is possible to clearly reduce the humming level in the interior in the speed range from 30 kilometers per hour to 80 kilometers per hour, flow noises at higher speeds as well as tension effects in the interior when sliding roofs are open. As acoustic resonances in the passenger compartment, which is opened when the sliding roof is open, can be reduced by means of the wind deflector according to the invention, very extensive roof openings to be opened can be achieved without an undesired impairment of the vehicle comfort occurring when these roof openings are released.
In a particularly advantageous embodiment of the invention, the deflector element is mounted on the housing element via the flexible membrane. The construction space requirement, the parts number and the weight of the wind deflector can hereby be kept low as the flexible membrane fulfils a double function. On the one hand, the flexible membrane serves to seal the deflector element against the housing element. On the other hand, the flexible membrane serves to mount the deflector element, wherein this is held on the housing to be able to move relative to this via the membrane.
A further embodiment is distinguished in that the inherently rigid housing element is formed from a first plastic. The flexible membrane is thereby formed from a second plastic which differs from the first plastic and is injection molded onto the housing element. Here, the wind deflector is at least partially formed as a two-component plastic component, wherein the housing represents a first plastic component and the flexible membrane represents a second plastic component of the two-component plastic component. A simple and cost-effective production is hereby able to be achieved. Furthermore, the housing element and the flexible membrane can hereby be adapted to their respective tasks. On the one hand, the housing element can be formed to be stiff and stable; on the other hand, the flexible membrane can be formed to be particularly soft or flexible, i.e., for example flaccid or moldable. Therefore, the flexible membrane can ensure an advantageous sealing and at the same time can move with the deflector element.
It has been shown to be particularly advantageous if at least one cover element formed from a first plastic is provided on which the flexible membrane formed from a second plastic which differs from the first plastic is injection molded. The housing element is thereby at least partially covered by the cover element arranged on the housing element. In other words, a component is provided which comprises the cover element and the flexible membrane and can be produced independently from the housing element and can be fastened to the housing element as a produced component. A time- and cost-effective production as well as a simple assembly of the wind deflector are hereby able to be achieved.
To achieve a particularly firm connection, it can be provided that the cover element is connected to the housing element which is preferably likewise formed from a plastic by friction welding.
In the case of a further advantageous embodiment of the invention it is provided that the flexible membrane and the deflector element are connected positively to each other. A firm connection which is simple to produce is hereby able to be achieved.
A further embodiment is distinguished in that at least one sealing lip is provided on the housing element to seal the housing element against a structure of the vehicle. The structure is, for example, the shell or the body of the vehicle. Unfavorable, undesirable air flows can be prevented by this sealing.
To achieve a particularly good sealing effect, the lip is preferably formed from a plastic and is injection molded onto the housing element in the scope of an injection molding process.
In order to be able to deflect or influence the air flowing onto the deflector element, in particular during a forward drive of the vehicle, in a particularly advantageous manner, in a further embodiment of the invention it is provided that the deflector element comprises a base body and at least one deflector lip which is formed separately from the base body and is connected to the base body, wherein the deflector lip is arranged above the base body in the vehicle vertical direction. For example, a particularly firm connection of the flexible membrane to the deflector element which is simple to produce can also hereby be produced in such a way that the flexible membrane is clamped between the base body and the deflector lip which is inserted into the base body.
In a further advantageous embodiment of the invention, the deflector lip is connected to the base body in a positive and/or frictional manner. A particularly firm hold is hereby ensured such that the deflector lip does not release from the base body even in the event of high vehicle speeds.
Finally, it has been shown to be particularly advantageous if the flexible membrane is formed in one piece with the deflector lip. The parts number can hereby be kept particularly low. Additionally, a particularly simple production of the wind deflector is able to be achieved, as the connection of the flexible membrane to the deflector element or to the base body accompanies the connection of the deflector lip to the base body.
Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments as well as by means of the drawings.